Geomagnetic Storms:Probabilities for significant disturbances in Earth's magnetic field are given for three activity levels: active, minor storm, severe storm

Updated at: 2016 Jul 11 2200 UTC

Mid-latitudes

0-24 hr

24-48 hr

ACTIVE

25 %

25 %

MINOR

05 %

05 %

SEVERE

01 %

01 %

High latitudes

0-24 hr

24-48 hr

ACTIVE

15 %

15 %

MINOR

30 %

30 %

SEVERE

30 %

30 %

Monday, Jul. 11, 2016

What's up in space

It's waiting for you: The most successful Aurora Photo Tour on Earth! 100% success rate 4 years in a row and winner of the TripAdvisor Certificate of Excellence Award. Join LapplandMedia's aurora tours in Abisko, Swedish Lapland!

SUBSIDING CHANCE OF STORMS: Earth is exiting a stream of solar wind flowing from an enormous coronal hole on the sun. As the wind speed subsides, the changes of storms are subsiding along with it. NOAA forecasters estimate a 45% chance of G1-class disturbances on July 11th, dropping to 30% on July 12th. Aurora alerts: text or voice

ELECTRIC BLUE GRAVITY WAVES: As July unfolds, sky watchers are seeing noctilucent clouds almost every night over northern Europe. Created by summertime water vapor freezing around meteor smoke in the upper atmosphere, the electric-blue forms can be mesmerizing. Consider this report from photographer Inta Nuke of Carnikava, Latvia: "July 10th was heavenly. I've never seen such bright, unusual shapes--almost mysterious." Almost. Scroll past Nuke's photo for an explanation:

The luminous swirls in Nuke's picture are a sign of gravity waves.

Gravity waves are, essentially, waves of pressure and temperature kick-started in the lower atmosphere by, e.g., powerful storm systems. Gravity does not vary inside the waves; they get their name from the fact that gravity acts as a restoring force that tries to restore equilibrium to up-and-down moving air. Gravity waves can propagate all the way from Earth's surface up to the mesosphere, where they imprint themselves on the the forms of noctilucent clouds.

Often, gravity waves break in the noctilucent zone, dumping their energy and momentum there. Laser radar studies of noctilucent wave structures can trace this energy and tell researchers a great deal about upper atmospheric circulation.

SPACE LIGHTNING OVER EUROPE: Summer thunderstorm season is underway in Europe. As a result, space lightning is on the rise. Martin Popek photographed these specimens over Nýdek in the Czech republic on July 10th:

These are sprites--an exotic form of upper atmospheric electricity sometimes called "space lightning" because they reach altitudes associated with meteors, noctilucent clouds and auroras. Some researchers believe they are linked to cosmic rays: Subatomic particles from deep space striking the top of Earth's atmosphere produce secondary electrons that, in turn, could provide the spark that triggers sprites.

Although sprites have been seen for at least a century, most scientists did not believe they existed until after 1989 when sprites were photographed by cameras onboard the space shuttle. Now "sprite chasers" routinely photograph sprites from their own homes. "They are easily detected by certain cameras," says lightning scientist Oscar van der Velde of the Technical University of Catalonia, Spain. "If a storm is in the mood, you may record one every few minutes." Give it a try!

Every night, a network of NASA all-sky cameras scans the skies above the United States for meteoritic fireballs. Automated software maintained by NASA's Meteoroid Environment Office calculates their orbits, velocity, penetration depth in Earth's atmosphere and many other characteristics. Daily results are presented here on Spaceweather.com.

In this diagram of the inner solar system, all of the fireball orbits intersect at a single point--Earth. The orbits are color-coded by velocity, from slow (red) to fast (blue). [Larger image] [movies]

Near Earth Asteroids

Potentially Hazardous Asteroids (PHAs) are space rocks larger than approximately 100m that can come closer to Earth than 0.05 AU. None of the known PHAs is on a collision course with our planet, although astronomers are finding new ones all the time.

These measurements are based on regular space weather balloon flights: learn more.

Approximately once a week, Spaceweather.com and the students of Earth to Sky Calculus fly "space weather balloons" to the stratosphere over California. These balloons are equipped with radiation sensors that detect cosmic rays, a surprisingly "down to Earth" form of space weather. Cosmic rays can seed clouds, trigger lightning, and penetrate commercial airplanes. Our measurements show that someone flying back and forth across the continental USA, just once, can absorb as much ionizing radiation as 2 to 5 dental X-rays. For example, here is the data from a flight on Oct. 22, 2015:

Radiation levels peak at the entrance to the stratosphere in a broad region called the "Pfotzer Maximum." This peak is named after physicist George Pfotzer who discovered it using balloons and Geiger tubes in the 1930s. Radiation levels there are more than 80x sea level.

Note that the bottom of the Pfotzer Maximim is near 55,000 ft. This means that some high-flying aircraft are not far from the zone of maximum radiation. Indeed, according to the Oct 22th measurements, a plane flying at 45,000 feet is exposed to 2.79 uSv/hr. At that rate, a passenger would absorb about one dental X-ray's worth of radiation in about 5 hours.